Sometimes, your chicken can develop problems where the crop won’t empty properly, leading either to sour crop or crop impaction. Most times, the bulge on the front of your chicken’s neck is most likely normal. Chickens have a built-in doggie bag — the crop, which is a bulge in the esophagus where food treasures from foraging are saved for leisurely digestion another time.
Sour crop: It feels big and squishy, and a foul smell may come from the chicken’s mouth.
Crop impaction: It feels full and hard.
Either way, the chicken looks miserable and loses weight. An impaction may also extend downstream, to the gizzard, where you can’t see the blockage. Possible causes of sour crop and crop impaction include:
Gorging on long grass, hay, straw, wood chips, or sand, or eating strange things like string, baler twine, or plastic
Diseases that slow down the movement of the gut, especially Marek’s disease, egg peritonitis, or lead poisoning
Damage to the gut from swallowed metal objects, or intestinal worms
You can be sure the bulge isn’t a problem by checking the chicken in the morning, before she has eaten — the bulge should be gone then.
Some of the reasons for crop problems are grim: Marek’s disease is fatal, and the prognosis for hardware disease, egg peritonitis, or severe gizzard impaction is awful. An experienced avian veterinarian can help determine the cause and offer surgical options, if it comes to that.
The sooner you seek help, the better for the bird’s chances of recovery. If consultation with an avian veterinarian isn’t an option, you can focus on the potentially treatable causes with the following advice:
Isolate the affected bird in a hospital pen and provide good nursing care. A cage with a wire floor and no bedding is preferable.
Feed a commercial mash or crumbled diet and offer poultry grit made of crushed granite. Add 2 tablespoons of vinegar to each gallon of drinking water, and make sure the solution is fresh and constantly available.
If the bird doesn’t seem to be improving after a week of your good nursing care, consider euthanizing it rather than allowing it to waste away.
You may be tempted to give mineral oil or other liquid lubricants by mouth to break up an impaction. However, force-fed mineral oil or other liquids may end up in the bird’s lungs, with a fatal result. Mineral oil doesn’t help much to break up an impaction anyway (granite grit is more helpful than anything else you can give).
You can prevent crop impactions in the following ways:
Keep grass mowed short where chickens forage.
Provide plenty of feeder space and always keep clean water available.
Sweep the pen occasionally with a magnetic pick-up tool, which you can purchase at a hardware store for $20 or less.
Be on the lookout for and remove old peeling paint from the flocks’ domain, because it can be a source of toxic lead.